The present disclosure relates to semiconductor memory devices, and more particularly, to a storage device including a nonvolatile memory device and/or a method of programming the same.
A semiconductor memory device may be classified into a volatile semiconductor memory device and a nonvolatile semiconductor memory device. A volatile semiconductor memory device has a high read and write speed but loses its stored data when a power supply is interrupted. A nonvolatile semiconductor memory device retains its stored data even when a power supply is interrupted. Thus, a nonvolatile semiconductor memory device may be used to remember contents that should be retained regardless of whether power is supplied or not.
Examples of a nonvolatile semiconductor memory devices include a MROM (mask read only memory), a PROM (programmable ROM), a EPROM (erasable PROM), a EEPROM (electrically EPROM), etc.
A typical example of a nonvolatile semiconductor memory device includes a flash memory device. Flash memory devices are being widely used as storage medium for voice data or video data of an information device such as a computer, a cellular phone, a PDA(personal digital assistant), a digital camera, a camcorder, a voice recorder, a MP3 player, a handheld PC, a game machine, a fax scanner, a printer, etc.
As demand for high capacity of a memory device increases these days, a MLC (multi-level cell) or a multi-bit memory device storing multiple bits in one memory cell is becoming common.